Lawn and garden tool

ABSTRACT

A hand-held portable lawn and garden tool having implements. A housing encloses a motor and at least two sets of gears arranged in cascade to provide low speed and high torque to the implements. Each set of gears is a sun gear with a plurality of planetary gears. Embodiments energized by battery packs, line power and internal combustion engines are disclosed.

FIELD OF THE INVENTION

1. The present invention relates to a lawn and garden tool and, moreparticularly to a portable tool having interchangeable implements whichoperate at high torque and low speed.

BACKGROUND OF THE INVENTION

2. Preparation and maintenance of lawns and gardens has great commercialand homeowner interest. Portable tools for work on lawns and gardens arelargely manually operated. In recent years, the use of powered tools hasincreased especially gasoline engine and electrically powered tools.These tools include lawn edgers, trimmers, cultivators, leaf blowers andhedge trimmers.

3. In U.S. Pat. No. 4,213,504 Schneider discloses a rotary, hand-heldapparatus for performing various soil working operations. The soilworking implements selectively include soil engaging tines, auger,drill, etc. The device may employ manual, electrical, gas, etc. powersources and cultivating, mulching, weeding, boring, etc. implements. Inone embodiment, an electric drill is secured to a handle to drive theimplements. In U.S. Pat. No. 4,293,041 Holmstadt et al disclose a powercultivator with a debris-excluding barrier and scraper, wherein thetillers are counter-rotated and include interdigitating tines whichengage and move the earth forwardly. Worm gears on the tillers aredriven by a common centrally located shaft mounted worm gears. Rickardet al in U.S. Pat. No. 5,802,724 and Everts et al in U.S. Pat. No.5,809,653 disclose a coupling for a split-boom power tool having anattachment which may include a hedge trimmer, line trimmer, pruner,blower or extension. The motor directly drives the attachment, therebeing no gearing therebetween. Lessig III et al in U.S. Pat. No. D252,879, disclose an electric-powered earth tiller.

4. In U.S. Pat. No. 2,975,848 Roberts discloses a portable power-drivendevice for boring holes which has a pinion gear on the power shaft ofthe motor and a larger driven gear meshing with the teeth of the piniongear. The driven gear is attached to the shaft of a chuck. In U.S. Pat.No. 4,366,871 Dieterle et al disclose a motor-driven screwdriver,wherein a planetary gear carrier carries a plurality ofcircumferentially-displaced planet gears meshing with a pinion driven bythe motor of the screwdriver. The screwdriver does not have a cascade ofplanet gears.

5. There is a need for a portable power-driven lawn and garden toolwhich has interchangeable implements.

BRIEF SUMMARY OF THE INVENTION

6. It is an object of the present invention to provide a portable,power-driven lawn and garden tool which has interchangeable implementsand the implements are driven at high torque and low speed.

7. In accordance with the teachings of the present invention, there isdisclosed a hand-held portable power driven tool for using a toolimplement. A housing encloses a permanent magnet electric motor. Themotor drives a planetary gear system having at least two sets of gearsarranged in cascade to provide a low speed, high torque output. Theoutput of the gear system drives the tool implement. The motor ispowered by at least one rechargeable battery pack, the battery packbeing replaceably inserted into the lawn and garden tool.

8. In further accordance with the teachings of the present invention,there is disclosed a portable, hand-held lawn and garden tool which hasa wand having a first end and an opposite second end. A handle isconnected to the first end and a housing is connected to the second end.A first set of gears is disposed in the housing, the first set of gearsbeing a sun gear engaging a plurality of planetary gears. A plurality ofsets of gears similar to the first set of gears are provided, the setsof gears being connected in cascade to an output shaft. A plurality ofimplements are provided. A selected one of the implements is removablyattached to the output shaft connected to the cascade of sets of gears,wherein the respective implements are interchangeable. Means areprovided for driving the sets of gears connected to the sets of gearssuch that the selected implement is driven at a selected high torque anda selected low speed dependent upon the arrangement of the plurality ofsets of gears.

9. Also in accordance with the teachings of the present invention, thereis disclosed a portable lawn and garden tool. The tool has a wand havinga first end and an opposite second end. A handle is connected to thefirst end. A motor in a housing is attached to the second end. A sourceof power is provided for the motor and a switch is disposed in thehandle to control the power to the motor. A first set of gears isattached to the motor within the housing. The first set of gears is asun gear engaging a plurality of planetary gears. A plurality of sets ofgears similar to the first set of gears is provided, the sets of gearsbeing connected in cascade. A plurality of implements are provided, arespective one of the plurality is removably attached to the cascade ofsets of gears. The respective implements are interchangeable. Theimplement is driven at a selected high torque and a selected low speeddepending upon the arrangement of the plurality of sets of gears.

10. Still further in accordance with the teachings of the presentinvention, there is disclosed, in a lawn-and-garden tool, thecombination of a housing having a longitudinal axis and further havingrespective side portions. Each of the respective side portions has anopening formed therein generally parallel to the longitudinal axis ofthe housing. At least one slide-in rechargeable battery pack isremovably received in each of the openings in the housing, such that thehousing is balanced. A permanent magnet motor is disposed within thehousing and selectively energized by the battery packs. A plurality ofplanetary gear systems are driven by the motor and arranged in cascadein the housing. An output shaft is powered by the planetary gearsystems, the output shaft having a relatively-low output speed and,conversely, a relatively-high output torque. A tool implement isdisposed externally of the housing and driven by the output shaft.

11. In another aspect of the present invention, there is disclosed atool having a drive means having a motor. A gear system having aplurality of planetary gear is driven by the motor. A single ring gearengages the plurality of planetary gears.

12. These and other objects of the present invention will becomeapparent from a reading of the following specification taken inconjunction with the enclosed drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

13.FIG. 1 is a perspective view of the tool of the present inventionwith one of the interchangeable implements adjacent to the tool andanother of the implements attached to the tool.

14.FIG. 2 is a bottom view of the tool with the adapter plate and outputshaft removed.

15.FIG. 3 is a partial cut-away view of the housing showing the motorand the sets of gears, the gears and a portion of the housing being incross section.

16.FIG. 4 is a side elevation of the motor and gear.

17.FIG. 5 is a bottom plan view of the motor showing the input gear.

18.FIG. 6 is a bottom plan view of the internally toothed annulus.

19.FIG. 7 is a top plan view of the sun gear.

20.FIG. 8 is a side elevation view of the sun gear of FIG. 7.

21.FIG. 9 is a top plan view of a planetary gear.

22.FIG. 10 is a side elevation view of the planetary gear.

23.FIG. 11 is a side elevation view of the output shaft.

24.FIG. 12 is a side elevation view of the output housing.

25.FIG. 13 is a top plan view of the output housing.

26.FIG. 14 is a bottom plan view of the adapter plate.

27.FIG. 15 is a side elevation view of the adapter plate.

28.FIG. 16 is a bottom elevation view of the tiller implement.

29.FIGS. 17-19 are a sequence of perspective views showing theattachment of the implement by a twist and lock system.

30.FIG. 17 is a perspective view of the tiller implement being movedtoward the tool.

31.FIG. 18 is a perspective view showing the pins on the tool beinginserted into the slots in the implement.

32.FIG. 19 is a perspective view showing the twisting of the implementwith respect to the tool to lock the pins in the slots.

33.FIG. 20 is a partial cut-away view showing the implement connected tothe output of the tool.

34.FIG. 21 is a view across lines 21—21 of FIG. 20 showing the batterywells in the housing.

35.FIG. 22 is a perspective view showing the rechargeable batteriesbeing inserted into the tool.

36.FIG. 23 is a perspective view of the handle portion of the toolhaving a replaceable battery pack.

37.FIG. 24 is an electrical diagram showing the connection of the powersource to the motor through a switch.

38.FIG. 25 is a perspective view showing the length of the wand beingadjusted.

39.FIG. 26 is a side elevation view of an alternate embodiment showingan angled handle having a connector therein to which is attached anelectrical cord to a source of power.

40.FIG. 27 is an alternate embodiment having a D handle attached to thehousing.

41.FIG. 28 is a perspective view of the tool having an internalcombustion engine.

42.FIG. 29 is a side elevation view of an auger-type implement.

43.FIG. 30 is a side elevation view of a side-by-side tiller implement.

44.FIG. 31 is a top plan view of the side-by-side tiller implement.

45.FIG. 32 is a side elevation view of one embodiment of an arm of thetiller implement.

46.FIG. 33 is an enlarged cross section view taken along the lines 33—33of FIG. 32.

47.FIG. 34 is a side elevation view of another embodiment of an arm ofthe tiller having a cutting blade.

48.FIG. 35 is an enlarged cross section view taken across the lines35—35 of FIG. 34.

49.FIG. 36 is an end view of a core drill mounted on the implementplate.

50.FIG. 37 is a side elevation view of the core drill mounted on theimplement plate.

51.FIG. 38 is a perspective view of a mixer mounted on the implementplate.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

52. The power-driven lawn and garden tool 10 has a wand 12 with a handle14 at one end and a housing 16 at the opposite end (FIG. 1). The housing16 contains an electric motor 18. The electric motor 18 may be apermanent magnet-type low voltage motor powered by batteries as will bedescribed or it may be a motor powered by standard AC current andconnected by wire to a standard convenience outlet. A battery-poweredmotor which has been found satisfactory is Model HC683LG manufactured byJohnson which has a nominal speed of approximately 7000 rpm and anoutput torque of approximately 20 inch ounces. Other types of electricmotors known to persons skilled in the art may be used. An electricswitch 20 is mounted in the tool 10 to control power to the electricmotor 18. Preferably, the switch 20 is located in the handle 14convenient to the hand of the operator of the tool.

53. On the inner wall of the housing 16, there is formed an annularinternal gear 24 (a ring gear) having spaced-apart teeth (FIGS. 2 and6). Also within the housing 16, there is disposed a plurality of sets ofgears 22 which are connected to the motor 18 (FIGS. 2-5). Each set ofgears 22 has a centralized sun gear 26 (FIGS. 7-8) which has teeth toengage cooperating teeth on a plurality of planetary gears 28 (FIGS.9-10). The gears are connected with pins 27. The output of the motor 18preferably is an output gear 30 (FIGS. 2, 4, 5) which drives the firstplanetary gear 28 in the first set of gears 22. The sets of gears 22 areconnected in a cascade or stacked manner in such a manner as tosignificantly reduce the speed of the sets of gears from the speed ofthe motor. The gear ratio, preferably is approximately 120:1 to 160:1 sothat the output of the sets of gears is less than 100 rpm at very hightorque. At a ratio of 120:1, the output torque is in the range of 6-12foot pounds. In a preferred embodiment, the output torque is 8.88 footpounds. The output speed is approximately 30-60 rpm with a preferredspeed being approximately 40 rpm. The output speed and torque isdependent on the speed of the motor and the arrangement and types ofgears used in the sets of gears 22 and may be selected duringmanufacture of the tool to provide the desired speed and torqueconsistent with the nature and types of implements which will be usedwith the tool 10. An advantage of the gear arrangement and the low speedoutput is to reduce drain on the batteries and provide a longer batterylife in the embodiment which is powered by batteries. The output of theset of gears 22 is connected to a selected implement 32 by means knownto persons skilled in the art. In a preferred embodiment (FIG. 2) theoutput of the sun gear 26 of the final set of gears 22 is formed as anelongated bar 34 which is received in and engages a cooperating slot 34′in an output shaft 31. It is further preferred that the output shaft 31pass through an output housing 33 which spaces the selected implementfrom the gear set 22 (FIGS. 11-13). The output shaft 31 has an enddistal from the gear set 22 which may be threaded to be received in acooperatively threaded nut-like means 35 connected to the adapter plate40. It is understood that other means, such as engaging gears, may beused to transmit force between the gear sets 22 and the implements 32.

54. A plurality of implements 32 are provided for use as a part of thetool. The implements 32 are all interchangeably attached to the housing16 by a simple easily connected/disconnected means (FIGS. 14-16). Apreferred means is a twist and lock type junction in which projectingpins 38 on the adapter plate 40 attached to the output of the sets ofgears 22 is engaged in slots or recesses 44 in the implement plate 42(FIGS. 17-19). The drive from the gear sets is directly engaged with therotatable center shaft in the implement as noted above. Other lockingmeans may be used.

55. The implements may be many and of varied types. The following aretypical examples and are not, in any manner, limiting. FIGS. 16-20 showa tiller (aerator) 36 having three angled arms 37 with pointed tips. Thetiller arms 37 may be straight or angled. The tiller arms may have aflat or sharpened leading edge to be selected depending upon the natureof the soil, i.e., sandy or loose (FIGS. 32 and 33) or clay soil, roots,etc. (FIGS. 34 and 35). Also, the tiller may have two arms or four arms.Additional implements may be an auger 32 which may be used for diggingpost holes, aerating and fertilizing (FIGS. 1 and 28), a core drillingimplement 60 for bulb planting (FIGS. 36 and 37), a mixer for concrete,driveway coating, etc. (FIG. 38) and other implements not limited tothose set forth herein. The tool 10 may also drive two cooperatingimplements such as side-by-side tillers 46 (FIGS. 30 and 31). One tilleris driven in a clockwise direction and the second tiller is driven in acounterclockwise direction. This type of tiller does not “walk” duringuse and provides more effective working of the ground. Thus, the lawnand garden tool of the present invention is a very versatile tool.

56. As shown in FIGS. 17-19, the implement 32 is easily attached andremoved from the tool 10. A center opening in the implement plate 42 isaligned with the nut-like means 35 on the adapter plate 40 such that thepins 38 on the adapter plate 40 are oriented with respect to therecesses 44 in the implement plate 42. Alternately, the pins 38 may beon the implement plate 42 and the recesses 44 may be in the drive plate.Also, the drive means on the output of the sets of gears (such as thebar 34) is simultaneously aligned with the slot in the center shaft ofthe implement. Preferably, the pins 38 have an enlarged head and therecesses are in the form of a slot having an end with an enlargeddiameter. The heads of the pins 38 are received in the enlarged diameterof the recesses and the adapter plate 40 and the implement plate 42 aretwisted with respect to one another such that the heads of the pins 38are locked in the more narrow portion of the recesses thereby securingthe implement plate 42 (and also the implement) with the adapter plate40 (and also the tool 10). Reversing the procedure removes the implement38 from the tool 10.

57. Also, the tool may be made as a single purpose tool with theimplement 32 permanently attached to the output of the gear system.Thus, a family of tools may be provided, each for a specific use.

58. The battery-operated embodiment preferably has at least onereplaceable, rechargeable battery 48 removably received in the tool 10(FIGS. 21, 22 and 23). Preferably, a battery pack is used and in oneembodiment, four battery packs such as “VERSAPAK” Model VP 100 Type 2made by Black and Decker are slidably received in pockets or wells 49formed in the outer surface of the housing 16. In this embodiment thebattery pack may have a positive center post and a negative annular ringwhich makes electrical contact with cooperating positive and negativeterminals 49, 50 in the pocket 50. This arrangement assures electricalcontact and prevents incorrect insertion of the battery pack. A meanssuch as a clamp, detent means or retaining pocket cover is provided tokeep the battery pack in the pocket and in electrical contact during useof the tool 10. It is understood by persons skilled in the art thatother types of batteries may be used and may be mounted in the tool in amanner different from the example described above. For example, arechargeable battery may be mounted in the tool with an electricalconnection for recharging the battery.

59. For example, FIG. 23 shows a battery pack 48 such as “SKIL 92931”made by S. B. Power Tool which is attached to the handle 14. The batterypack 48 may have prongs which make electrical contact with cooperatingreceptors in the handle 14. An electrical switch 20 may be incorporatedin the handle 14. The switch 20 may be load sensitive to open and removepower from the tool if the current spikes due to the tool locking up orjamming.

60.FIG. 24 shows a typical electrical wiring diagram. If the battery isformed from more than one battery pack, the batteries are connected inseries. In a four battery pack, each battery pack has an output voltageof 3.5V to power the 14V motor. It is understood that the voltage of themotor may be different from the example given herein and battery packshaving the appropriate voltage would be used. An electrical switch 20 isto provide the operator with control over the power to the tool. Atypical layout of the disposition of the battery connections in the tool10 is shown in FIG. 21.

61. The tool 10 may be used by a standing, kneeling or seated operatorand, to have a versatile tool which can be used in all of these posturesand also to provide more comfortable use by operators of differingheights, the wand 12 may be made adjustable (FIG. 25). A telescopingwand may be provided with adjustable stop and locking means known topersons skilled in the art. Alternately, the wand 12 may be made with ashorter length and a separate embodiment may have a longer length.

62. The tool 10 may be powered by standard commercially availableelectrical power such as 115V AC. FIG. 26 shows an angled handle 14 onthe first end of the wand 12 with an electrical connector formed in theangled handle 14. An electrical cord is connected to the connector inthe handle 14 and extends to a convenience outlet for 115V AC power. Theelectrical cord may also be connected to a source of power carried as aback pack or waist pack by the operator. The switch 20 is placed in thehandle 14 for ready access to the hand of the operator. Also, anauxiliary balance handle 54 may be mounted on the wand 12 to assist theoperator in two-handed use of the tool 10. The balance handle 54 may befixedly or adjustably mounted on the wand and may include an extensionto assist in torque control.

63. In still another embodiment (FIG. 27), a D-shaped handle 56 may beformed on the first end of the wand 12 or may be formed on the housing16. An auxiliary handle 54 may be included to steady the tool againstrotation while in use. Other handle shapes such as a pistol type handlemay be used.

64. The tool 10 may also be powered by an internal combustion engine 58(FIG. 28). The output from the engine 58 is used to drive the sets ofgears 22 in a manner similar to the drive by electrical motors. A switchis included in the handle to turn off the engine 55.

65. Thus, there is disclosed a compact, portable tool which hasinterchangeable implements and is used for lawns and gardens. Due to lowspeed, high torque output obtained from the engine gearing between thepower source and the implements, a very efficient tool is provided.

66. Obviously, many modifications may be made without departing from thebasic spirit of the present invention. Accordingly, it will beappreciated by those skilled in the art that within the scope of theappended claims, the invention may be practiced other than has beenspecifically described herein.

What is claimed is:
 1. In a hand-held portable power driven tool forusing a tool implement, the improvement comprising: a housing enclosinga permanent magnet electric motor, the motor driving a planetary gearsystem having at least two sets of gears arranged in cascade to providea low speed, high torque output, the output of the gear system drivingthe tool implement, the motor being powered by at least one rechargeablebattery pack, the battery pack being replaceably inserted into the lawnand garden tool.
 2. The tool of claim 1 , wherein the gear systemreduces the speed of the tool implement to less than 100 rpm.
 3. Thetool of claim 2 , wherein the speed of the tool implement isapproximately 30 to 60 rpm.
 4. The tool of claim 1 , wherein the torqueapplied to the tool implement is approximately 6 to 12 foot pounds. 5.The tool of claim 1 , wherein the housing is attached to one end of awand and a handle is attached to the opposite end of the wand.
 6. Thetool of claim 1 , further comprising a single ring gear disposed withinthe housing and engaging the planetary gear system.
 7. The tool of claim1 , wherein the at least one battery pack is inserted in the housing. 8.The tool of claim 1 , wherein the at least one battery pack is insertedinto a handle connected to the housing.
 9. A portable, hand-held lawnand garden tool comprising: a wand having a first end and an oppositesecond end, a handle connected to the first end, a housing connected tothe second end, a first set of gears in the housing, the first set ofgears being a sun gear engaging a plurality of planetary gears, aplurality of sets of gears similar to the first set of gears, the setsof gears being connected in cascade to an output shaft, a plurality ofimplements, a selected one of the implements being removably attached tothe output shaft connected to the cascade of sets of gears, wherein therespective implements are interchangeable, means for driving the sets ofgears connected to the sets of gears such that the selected implement isdriven at a selected high torque and a selected low speed dependent uponthe arrangement of the plurality of sets of gears.
 10. The tool of claim9 , wherein the means for driving the sets of gears is an electric motordisposed in the housing.
 11. The tool of claim 10 , wherein the electricmotor is battery powered.
 12. The tool of claim 11 , wherein at leastone rechargeable battery pack is disposed in the tool and electricallyconnected to the motor through an electrical switch mounted in the tool.13. The tool of claim 10 , wherein the electric motor is powered througha line cord connected to a source of power.
 14. The tool of claim 9 ,wherein the means for driving the sets of gears is an internalcombustion engine connected to the tool.
 15. The tool of claim 9 ,wherein the implement is selected from the group consisting of a tiller,an auger, a mixer and a core driller.
 16. The tool of claim 9 , whereinthe gears reduce the speed of the implement to less than 100 rpm. 17.The tool of claim 16 , wherein the speed of the implement isapproximately 30 to 60 rpm.
 18. The tool of claim 9 , wherein the torqueapplied to the implement is approximately 6 to 12 foot pounds.
 19. Thetool of claim 9 , wherein the wand has an adjustable length such thatthe tool may be long for use by a stand-up operator and may be short foruse by a kneeling operator.
 20. The tool of claim 9 , further having anauxiliary handle attached to the wand, the auxiliary handle facilitatinguse and balance of the tool.
 21. The tool of claim 9 , wherein theimplement is removably attached to the housing by a twist and lock-typeconnector.
 22. The tool of claim 9 , further comprising a single ringgear disposed within the housing and engaging the first set of gears.23. A portable hand-held lawn and garden tool comprising: a wand havinga first end and an opposite second end, a handle connected to the firstend, a motor in a housing attached to the second end, a source of powerfor the motor, a switch in the handle to control power to the motor, afirst set of gears connected to the motor within the housing, the firstset of gears being a sun gear engaging a plurality of planetary gears, aplurality of sets of gears similar to the first set of gears, the setsof gears being connected in cascade, a plurality of implements, aselected one of the plurality being removably attached to the cascade ofsets of gears and to the housing, wherein the respective implements areinterchangeable, such that the selected implement is driven at aselected high torque and a selected low speed depending upon thearrangement of the plurality of sets of gears.
 24. The tool of claim 23, wherein the motor is battery-powered, at least one rechargeablebattery pack being disposed in the tool.
 25. The tool of claim 24 ,wherein four rechargeable battery packs are provided, the battery packsbeing removably disposed on four sides of the motor housing.
 26. Thetool of claim 23 , wherein the implement is selected from the groupconsisting of a tiller, an auger, a mixer and a core driller.
 27. Thetool of claim 23 , wherein the implement is a pair of tillers disposedside-by-side such that one of the tillers rotates in a clockwisedirection and the other tiller rotates in a counterclockwise direction.28. The tool of claim 23 , wherein the gears reduce the speed of theimplement to less than 100 rpm.
 29. The tool of claim 28 , wherein thespeed of the implement is approximately 30 to 60 rpm.
 30. The tool ofclaim 23 , wherein the torque applied to the implement is approximately6 to 12 foot pounds.
 31. The tool of claim 23 , wherein the wand has anadjustable length such that the tool may be long for use by a stand-upoperator and may be short for use by a kneeling operator.
 32. The toolof claim 23 , further having an auxiliary handle attached to the wand,the auxiliary handle facilitating use and balance of the tool.
 33. Thetool of claim 23 , wherein the implement is removably attached to thehousing by a twist and lock-type connector.
 34. The tool of claim 23further comprising a single ring gear disposed within the housing andengaging the first set of gears.
 35. In a lawn-and-garden tool, thecombination of a housing having a longitudinal axis and further havingrespective side portions, each of which has an opening formed thereingenerally parallel to the longitudinal axis of the housing, at least onerechargeable battery pack removably received in each of the openings inthe housing, such that the housing is balanced, a permanent magnet motorwithin the housing and selectively energized by the battery packs, aplurality of planetary gear systems driven by the motor and arranged incascade in the housing, an output shaft powered by the planetary gearsystems, the output shaft having a relatively-low output speed and,conversely, a relatively-high output torque, and a tool implementexternally of the housing and driven by the output shaft.
 36. A toolcomprising: a drive means having a motor, a gear system having aplurality of planetary gears driven by the motor, and a single ring gearengaging the plurality of planetary gears.
 37. The tool of claim 36 ,wherein the motor is a permanent magnet motor powered by at least onebattery.
 38. The tool of claim 37 , wherein the tool has a housingcontaining therein the motor and the gear system, the at least onebattery being replaceably disposed in the housing.
 39. The tool of claim37 , wherein the tool has a handle connected to the motor and gearsystem, the at least one battery being replaceably disposed in thehandle.